EXTRA! EXTRA! Plate Repairs- THIS COULD BE IT!

[Richard Snelson]

Wim en Debby wrote:
> 
> Hi List,
> l know this method for several years. l have also good experiance with
> it . Here in Belgium its called Metalock. lt was made to repair cast
> iron peaces like huge waterpumps and engine-blocks. But cast-iron
> frames from piano's and grands, are easy to fix. It is cheap and there
> is no risc, like there is with  welding, that your plate breaks at
> another place.
> best regards,
> Wim Vermeyen
> Wim's Piano Service
> Ekeren, Belgium
> wim.debby@village.uunet.be
> 
>      -----Oorspronkelijk bericht-----
>      Van: Robert Goodale <Robert.Goodale@NAU.EDU>
>      Aan: pianotech@ptg.org <pianotech@ptg.org>
>      Datum: woensdag 16 december 1998 7:04
>      Onderwerp: EXTRA! EXTRA! Plate Repairs- THIS COULD BE IT!
> 
>      While at Yamaha an amazing new method for repairing cracked
>      piano was shared by another member of the group.  This is a
>      completely new technique and is unlike anything previously
>      discussed.  This group member also brought a video tape for
>      show and tell which put everyone in awe.  Even LeRoy was
>      dumbfounded and is now wanting more information.
> 
>      This is no joke folks, read on...
> 
>      This crack repair method was developed originally for
>      repairing cracked cast iron engine blocks and other heavy
>      machinery.  It involves no welding whatsoever.  Instead a
>      series of very specially designed screws are inserted into
>      the crack which quite literally pull the crack together
>      stronger than it was before.  When the repair is complete it
>      is almost invisable.  This may sound to good to be true but
>      the tape demonstrates this clearly.  Two flat pieces of cast
>      iron were fastened together in a butt joint by a single one
>      of these screws, and was then hooked on each end with a
>      heavy chain.  The chain was then connected to a wench which
>      lifted a 350 pound engine block.  The bond held perfectly.
>      A complete series of pins overlapping in a crack seals the
>      crack permanently and stronger than it was originally.  On
>      bench tests these repairs were shown to be completely air
>      tight at 80 PSI.
> 
>      Ok, so here's how it works.  The screws are designed to dig
>      in to the cast iron.  They must go into a pre-drilled hole
>      using a special bit. The holes are also taped. The secrete
>      is in the screw threads which are cupped sharply upward.
>      The top half of the screw has a countersunk collar which
>      pulls tightly into the hole in the opposing direction of the
>      cupped threads.  The screw is driven into the cast iron
>      using an air drill until the torque breaks of the head.  The
>      result is that the cast iron is clamped tightly together
>      *internally*.  A series of these screws are installed to
>      follow the crack side by side.  Then an overlapping series
>      of screws are inserted in a second pass. The remains of the
>      torqued-off heads are ground away smooth.  No welding, no
>      mess.  This type of repair can even be made inside the piano
>      without plate removal.  There are several types of these
>      special screws which can be used on various types of cracks,
>      even on angles or in corners.  They are also available in
>      various lengths.  The video presentation was extremely
>      convincing and had us talking about it for the remainder of
>      the week.
> 
>      This group member's local chapter recently decided to try
>      this repair as a joint project.  The inventor of this
>      technique was personally present and assisted in explaining
>      and then demonstrated the repair.  This proceedure is brand
>      new and this was the first such repair made on a piano.  I
>      think we can all pretty much expect to hear a lot about this
>      very soon.
> 
>      This repair system is called the "CastMaster" by a company
>      called Lock-N-Stitch.  They do have a web page.  Check it
>      out and be amazed.
> 
>      Lock-N-Stitch
> 
>      Follow the link to "Information about Cast Master".  After
>      you've read the text and looked at the pics, go to the link
>      that demonstrates the complete repair.
> 
>      Enjoy!
> 
>      Rob Goodale, RPT
I will be doing a LockNstitch on a 1906 Conover plate sometime in the
next two weeks. Cracks are in (2) the pinblock struts, which load in
tension. Piano has four individual pinblocks. I live in Central Ill
(Clinton) and would welcome any one wanting to join the experience.
Richard O. Snelson Phone 217-935-4215